Preheat the oven to 350 degrees F.

Spray the casserole dish with cooking oil.

Melt the butter in a small saute pan and add the onion already diced until the onions are cooked and soft.

Add the hash browns just enough for them to be soft.

In a separate frying pan start to cook the sausage.

In a large bowl combine the milk, eggs, salt, pepper and mustard. Mix well.

Combine the ingredients by laying out the onions and hash browns in the casserole dish first.

Next add the bread crumbs, then the left over meat or sausage.

Lastly, pour the milk mixture over the top and add the cheese.

Bake it for about 45 minutes.